Recent progress on CO-rich syngas production via CO 2 gasification of various wastes: A critical review on efficiency, challenges and outlook

Carbon monoxide (CO) is a highly valuable component of syngas which could be used to synthesize various chemicals and fuels. Conventionally, syngas is derived from fossil-based natural gas and coal which are non-renewable. To curb the problem, CO gasification offers a win-win solution in which CO is converted with wastes to CO, achieving carbon emission mitigation and addressing waste disposal issue simultaneously. In this review, gasification of various wastes by CO with particular focus given to generation of CO-rich syngas is presented and critically discussed. This includes the effects of operating parameters (temperature, pressure and physicochemical properties of feedstocks) and advanced CO gasification techniques (catalytic CO gasification, CO co-gasification and microwave-driven CO gasification). Furthermore, associated technological challenges are highlighted and way forward in this field are proposed.